Looks like the cell had data with 16 hex chars, so I used the following sql code to change it;
update tblQuickFixEngineering
set InstalledOn = ''
where len(InstalledOn)>10
I still had issue, so amended the code, here is my working sql;
Select Top 1000000 tblAssets.AssetID,
  tblAssets.AssetName,
  tsysOS.OSname,
  tblAssets.Username,
  tblAssets.IPAddress,
  tblAssets.Description,
  Max(Convert(date,tblQuickFixEngineering.Lastchanged)) As lastPatchDate,
  tblAssets.Lastseen
From tblQuickFixEngineering
  Join tblAssets On tblAssets.AssetID = tblQuickFixEngineering.AssetID
  Join tsysOS On tblAssets.OScode = tsysOS.OScode
Where tblQuickFixEngineering.InstalledOn Like '%/%'
Group By tblAssets.AssetID,
  tblAssets.AssetName,
  tsysOS.OSname,
  tblAssets.Username,
  tblAssets.IPAddress,
  tblAssets.Description,
  tblAssets.Lastseen
Order By lastPatchDate
Here is the Chart code...must save this with "Chart:" at the start of the title;
Select Top 1000000 Case
    When webXXXXXXXXXXXXXX.lastPatchDate >= DateAdd(day,
    -30, GetDate()) Then '1. Within 1 month'
    When webXXXXXXXXXXXXXX.lastPatchDate < DateAdd(day,
    -31, GetDate()) And webXXXXXXXXXXXXXX.lastPatchDate
    >= DateAdd(day, -60, GetDate()) Then '2. Within 2 months'
    When webXXXXXXXXXXXXXX.lastPatchDate < DateAdd(day,
    -61, GetDate()) And webXXXXXXXXXXXXXX.lastPatchDate
    >= DateAdd(day, -90, GetDate()) Then '3. Within 3 months'
    Else '4. more than 3 months' End As DateRange,
  count(*) As NumberOfAssets
From webXXXXXXXXXXXXXX
Group By Case
    When webXXXXXXXXXXXXXX.lastPatchDate >= DateAdd(day,
    -30, GetDate()) Then '1. Within 1 month'
    When webXXXXXXXXXXXXXX.lastPatchDate < DateAdd(day,
    -31, GetDate()) And webXXXXXXXXXXXXXX.lastPatchDate
    >= DateAdd(day, -60, GetDate()) Then '2. Within 2 months'
    When webXXXXXXXXXXXXXX.lastPatchDate < DateAdd(day,
    -61, GetDate()) And webXXXXXXXXXXXXXX.lastPatchDate
    >= DateAdd(day, -90, GetDate()) Then '3. Within 3 months'
    Else '4. more than 3 months' End
Replace webXXXXXXXXXXXXXX with the page code from upper report...eg the bold text from my example...
http://lansweeper/report.aspx?det=
web50rep31d4d1c95f3d42a5b34325daca965d28&title=Last+Patch+Installed
I have amended the chart for within 1,2,3 and over 3 months as I thought 7 days was a little too early.
When you’re in Lansweeper, 
•	add a widget to the page
•	Select Pie chart
•	Select "Chart: Last Patch Installed"
•	Legend on right or left
•	Save the widget